Condensation product and method of preparing the same



Patented Jam 18, 1944 CONDENSATION PRODUCT AND METHOD OF PREPARING THESAME Gaetano F. DAlelio, Pittsfield, Mass., asslznor to General ElectricCompany, a corporation of New York No Drawing. Application December 3,194 1,

' Serial No. 421,491

4 Claims. (erase-s9) resents hydrogen or anymonovalent hydrocar- I bonradical of not more than six carbon atoms, and R represents hydrogen orany monovalent hydrocarbon radical, whether saturated or unsaturated,substituted or unsubstituted, aliphatic, carbocyclic, aryl, orheterocyclic, monoor polynuclear, etc., and n has a value of 1 or 2.Examples of suitable hydrocarbon radicals represented by R are aliphatic(e. g. methyl, ethyl, propyl, isopropyl, butyl, secondary butyl,butenyl, amyl, hexyl, allyl, etc.) including cycloaliphatic e. g.(cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cycloheptyl,etc.); aryl (e. g. phenyl, diphenyl, naphthyl, etc); 'alkyl substitutedaryl (e. g. tolyl, xylyl, ethylphenyl, isopropylphenyl, allyl phenyl,etc); aryl substituted alkyl (e. g. benzyl, phenylethyl, phenyl allyl,etc.) and. their homologues, as well as those groups with one or more oftheir hydro-. gen atoms substituted by a halogen. Specific examples ofhalogeno-substituted hydrocarbon radicals are chlormethyl,chlorcyclohexyl, chlorphenyl, dichlorphenyl, ethyl chlorphenyl, phenylchlorethyl, bromethyl, bromtolyl, etc. Preferably R and R in the aboveformula are hydrogen.

The novel derivatives represented by the above formula when n equals 1may be prepared by reacting, in the cold, a concentrated aqueoussolution of one mol of a substituted or unsubstituted monocarbinol ureaor thiourea of the formula with a concentrated aqueous solution of onemol of a substituted or unsubstituted urea or thiourea of the formula YIll N cold concentrated solution of a dicarblnol urea or thiourea with acold concentrated solution of a urea or thiourea in the mol ratio of1:2.

As a more specific example of the preparation of my novel startingmaterials, a, cold concentrated solution of 2 mols of urea is mixed witha cold concentrated solution of dimethylol urea and the subsequentreaction allowed to proceed in the cold with the formation ofsymmetrical dicarbamidomethyl urea having the formula H2NCONH(CH2NHCONH)2H.

Examples of monocarbinol or dicarbinol ureas, other than themonomethylol or dimethylol ureas which may be used are: monoanddimethylcarbinol urea and thiourea, monoand di-methylol phenyl urea andthiourea, monoand di-methylol allyl urea and thiourea, etc.

Examples of substituted ureas and thioureas which may be used in thepreparation of all or some of my reactive derivatives are the mono-, orN, N-di-alkyl or aryl-ureas or thioureas, for instance, mono-,symmetrical di-methyl ureas or thiourea, N-methyl N'-ethyl urea orthiourea, phenyl urea or thiourea, N-methyl N'-phenyl urea or thiourea,etc.

Preferably the cold concentrated solutions of the two reactants aremixed and held at a temperature between0 and 20 C. The products of thereaction crystallize out on standing or on evaporation of the excesswater at or below room temperature under atmospheric or subatmosphericpressures. Alternatively, the product may be recovered by adding to theaqueous solution of the reaction product a suitable Water-miscibleprecipitant for the. reaction prodnot, which precipitant is incapableofreacting with the desired product at operating temperatures.

The resulting compounds may be resinified by reaction with aldehydes oraldehyde engendering substances, preferably under the influence of heat,the unsubstituted derivatives of the formula NH2CYNH(CH2NHCONH)1;H beingmost easily resiniiied under such conditions. The relative ease ofresinification decreases with increased replacement of the varioussubstitutable hydro gens by hydrocarbon radicals. Resiniflcation may beaccomplished by heating the reactants alone, in inert mediums, or ininert solvents such as water. Resinification may be accelerated by theaddition or presence of basic materials, acidic materials, neutral,acid, or alkaline salts. Reactive media may likewise be used to achieveresinification as hereinafter shown.

This novel class of organic compounds may be mixed with resinintermediates containing carbinol (CR2OH) groups, such as monomethylolureas, dimethylol ureas, phenol methylols, the methylols of cyclicamidines, e. g., methylol me1a mines, methylol guanazoles, etc; thencoor interresinified alone or in the presence of other modifying bodiesto give intercondensed resins.

The novel compounds of this invention, particularly the highlysubstituted compounds, may be used as plasticizers for many resins. Inmany cases they themselves become resinous during the plasticizingprocess, while in other cases they condense with the other resinousintermediate during manufacturing operations. Specifically, thesematerials may be used (1) unconverted as plasticizers, (2) partly orcompletely converted as plasticizers, (3) partly or completelyintercondensed to exert a plasticizing effect. The final andintermediate resins prepared from the novel materials of this inventionalone or with the modifications expressed herein are extremelycompatible with many other natural or synthetic resins in theirintermediate or ultimate stages.

Before, during, or after the resinification process, the reactionbetween the aldehyde or mixture of aldehydes and the novel compounds ofthis invention may be modified by the presence of suitable amounts of alarge class of compounds, for example, hydroxy compounds, e. g. methyl,ethyl, propyl, isopropyl, butyl, amyl, tertiary amyl, benzyl, furfuryi,tetrahydrofurfuryl, cyclohexyl, phenethyl, naphthyl, polyvinyl, allyl,methallyl, crotyl, i-chlorallyl, propargyl, 2-chlorallyl, cinnamyl,alcohols, etc., glycol, diethylene glycol, triethylene glycol,polyethylene oxide, glycerine, pentaerythritol, saligenin, phenol,cresol, xylenol, resorcinol, catechol, pyrogallol, etc., chlorohydrin,epi-chlorohydrin, nitrobutanol, diacetone alcohol, ethylene oxide,propylene oxide, etc., ammonia and its amino, amido, r imino compounds,e. g., methylamine, dimethylamine, hydroxylamine, hydrazine, phenylhydrazine, diamylamine, stearyl amine, cyclohexyl amine, aniline,di-phenylamine, diaminobenzene, triaminobenzene, aminophenol, nitroaniline, piperazine, ethanclamine, di-isopropanolamine, triethanolamine,propanolamine, ethylene diamine, formamide, acetamide, propionamide,lauramide, acrylic amide, methacrylic amide, atropic amide, malonicdiamide, itaconic diamide, succinic diamide, citraconic triamide,benzamide, phthalic diamide, phthalimide, benzosulfimide, aminobenzenesulfonamide, benzene disulfonamide, benzene trisulfonamide, anthranilicesters, anthranilamide, salicylamide, para-phenyl benzene sulfonamide',tolyl amide, etc; the amino 1,3,5-triazines, e. g., 2,4,6-trlamino1,3,5-triazine, 2-amino 1,3,5-triazine, 2,4-diamino 1,3,5-triazine; thediazines, e. g., 2,4,6-triaminopyrimidine, the diamino pyrimidine thioesters; the amino 1,2,4- triazoles, e. g., guanazole, phenyl guanazole,dihydrazino 1,2,4-pyrrodiazole, guanazo-guanazole, imidurazo-guanazole;the amino 1,2-diazoles, e. g., 3,5-diaminopyrazoley-the urea typecompounds, e. g., urea, methylurea, monomethylol urea, phenyl urea,thiourea, phenyl thiourea, unsymmetrical diphenyl urea, unsymmetricalethyl phenyl urea, hydroxy urea, ethanol urea, unsymmetrical diethanolurea, guanidine, aminoguanidine, biguanidine, di-cyandiamide, guanylurea, guanyl thiourea; the proteins, e. g., casein, soya bean protein,alfalfa protein, gelatin, coffee bean protein, alkyd resins having freehydroxyl groups such as glyceryl phthalate, coil-modified glycerylphthalate, diethylene glycol succlnate, triethylene glycol maleate,glyceryl maleate, etc.; nitriles, e. g.,

, acetonitrile, propionitrile, butyronitrile, benzonitrile,acrylonitrile, methacrylonitrile, atroplc nitrile, ethylene cyanohydrin,acetone cyanohydrin, aminoisobutyronitrlle, aminoacetonitrile, etc.;

esters such as lactic esters, hydroxy isobutyric esters, acetoaceticester, malonic esters, etc.

The final and intermediate resins and condensation products preparedfrom the novel materials of this invention alone or with themodifications already expressed are extremely compatible with many othernatural or synthetic resins in their intermediate or ultimate stages.

This novel class of compounds, when reacted with aldehydes, alone orwith modifications, will form self-curing aminoplasts by condensationwith curing reactants, such as chloroacetonitrile, nitrourea, glycine,amino-propanol hydrochloride, mono-, dior tri-chloroacetamides, alpha,betadibromopropionitrile, alpha, beta-dichloropropionitrile,alpha-methyl, alpha, beta-dichloropropionitrile, aminoacetamidhydrochloride, ethylene diamine monohydrochloride, sulfamic acid,chloroacetyl urea, citric diamicle, phenacyl chloride and othersmentioned, for example, in my copending applications Serial No. 346,962,filed July 23, 1940, and Serial No. 354,395, filed August 2'7, 1940,both of which applications are assigned to the same assignee as thepresent invention.

The initial reaction leading to the formation of the new condensationproducts of ingredients comprising an aldehyde and my novel compoundsmay be carried out at normal or at elevated temperatures, at atmosphericor superatmospheric pressures, and in the presence or absence of an acidor of an alkaline condensing agent which may be either a dlrect catalystor a reactant catalyst. A catalytic reactant or reactant catalyst isdefined as a substance which accelerates the reaction between thealdehyde and the aldehyde reactable component or components while ititself becomes an integral part of the condensation product. Preferablythe reaction between the components is started under alkaline condiions.

Examples of other substances yielding alkaline aqueous solutions may beused in obtaining alkaline conditions for the initial condensationreaction are alkalls such as sodium, potassium and calcium hydroxides,sodium and potassium carbonates, mono-, diand tri-amines, etc. Bestresults are obtained by causing the condensation reaction between theprimary components to take place in the presence of a primarycondensation catalyst and a secondary condensation catalyst. To obtaincondensation products having optimum timeor storage-stabilitycharacteristics, I have found that the primary catalyst should be amember of the class consisting of (1) nitrogen-containing basic tertiarycompounds that are aldehyde-non-reactable, e. g. tertiary amines such astrialkyl (for example, trimethyl, triethyl, etc.) amines, triaryl (forexample, triphenyl, etc.) amines, etc. and (2) nitrogen-containing basiccompounds that are aldehyde-reactable, for instance, ammonia, primaryamines (e. g. ethyl amine, propyl amine, etc.) and secondary amines (e.g. dipropyl amine, dibutyl amine, etc.). Catalytic reactants that may beused include substances such as tri-carbamidomethyl amine,N(CH2NHCONH2)3 or other substituted or unsubstituted mono-, diortri-carbamidomethyl amines or substituted or unsubstituted mono-, diortri-(mono-carbinol-ureidomethyl) amines such as are disclosed in mycopending applications Serial Nos. 409,017 to 409,022, inclusive, filedAugust 30, 1941, and assigned to the same assignee as the presentinvention.

The secondary condensation catalyst, which ordinarily is used in anamount less, than the amount of primary catalyst, should be a fixed andthereafter at any stage of the original reaction, I may add theremaining aldehyde-reactable ingredient or ingredients. Or I maycondense or partially condense my novel compounds with an aldehyde, addthe resulting product to a urea-aldehyde, a phenol-aldehyde, or someother partial condensation product of an aidehyde and an aldehydereactable body and then cause the reaction to proceed further. Stillother ways may be employed in combining the components in producing themodified or unmodifled products of this invention, as will readily beunderstood by those skilled in the art from the following examplescovering the preparation of resinous products from monocarbamidomethylurea having the formula NHzCONHCHzNHCONHa or symmetricaldi-carbamidomethyl urea having the formulaNI-IzCONHCHzNHCONHCI-IaNHCONHz The aqueous formaldehyde used in this andsubsequent examples was a commercial formaldehyde solution containing37.5 per cent CH2O.'

The mono-carbamidomethyl urea was prepared by mixing cold concentratedsolutions of 1 mol monomethylol urea and i inol urea and recovering themonocarbamidomethyl derivative which crystallized from the mixture. Thisderivative was mixed with the formaldehyde and sodium hydroxide solutionand the mixture refluxed at the boiling temperature of the mass for 20minutes. A resinous syrupy product was obtained which was cloudy whilehot and which precipitated on cooling. The syrup had a pH of 6.5. Whentested at 140 C. the resinous syrup has a very slow and rubbery cure.The addition of a small amount of (for example, 0.5 per cent by weight)a curing agent, specifically chloroacetamide, produced a compositionhaving a fast, hard cure at 140 C.

The above ingredients were refluxed for 30 min utes. The syrupy productwas very thick and clear while hot. On cooling, a white paste developed.At 130 C. the paste melted down and cured quickly to a very hard mass.This example illustrates an acid catalyzed condensation sincecommercialiormaldehyde contains formic acid.

Example 3 Mol ratio Pans by (approx.) weight Dl-carbamidomethyl urea(containing 5% H10) l 100. f- Aqueous formaldehyde. 4 157. 0 NaOH (in 8parts water) 0.01 t 0.16

, cent resin solids. It did not cure alone at C.

The addition of small amounts of various curing agents to the syrupcaused it to cure or harden within reasonable periods of time. A good,hard cure was obtained with chloroacetamide and phenacyl chloride. Thecure obtained with citric acid and alpha, beta-dibromopropionitrile wasvery fast. Chloral urea gave a slow cure as compared with the previouslymentioned agents.

A molding compound was made by mixing 9 parts alpha flock with asolution of 0.11 part chloroacetamide 'n 21 parts of the above resinsyrup and air-drying the mixture for 48 hours. The compound has goodmoldability and a hard cure when molded at C. and 6000 pounds per squareinch pressure for 5 minutes. The molded product waslight-colored. A wellcured piece may also be obtained by using alpha,betadichloropropionitrile in place of chloroacetamide in the aboveexample.

The above was refluxed for 30 minutes to produce a syrup which was clearwhile hot and at room temperature. It had a. pH of 8.7. At C. the syrupdid not cure without the addition of a curing agent. It had a fast curewith chl0- roacetamide and alpha, beta dichloropropionitrile, a rubberycure with polysalicylic acid, a very fast cure with nitrourea, and aslow cure with oxamide. A molding compound prepared from 22 parts syrup,9.2 parts alphaflock, and 0.11 part chloroacetamide, using the mixingand molding procedure set forth in the previous example, had goodmoldability, a hard cure, and was light-colored. Similar results may beobtained by the use of alpha, beta-dichloropropionitrile in place of thechloroacetamide.

Example 5 Mol ratio (approx) Example 6 Mol ratio Parts by (approx.)weight Aqueous di-carbamidomcthyl urm (28% couc.) 1 35.7 Aqueous N(CHNHCONH;CH;OH): (25% cone. 0.1 6.3 Aqueous formaldehyde 4 l5. 7

The above were refluxed for 30 minutes. The resultant syrup was clearwhile hot and cloudy on cooling. It had a pH of 5.35 and contained 47per cent resin solids. At 130 C. the syrup did not cure alone. A goodcure was obtained with small additions of citric acid. Chloroacetamidegave a very good cure.

Following the procedure set forth in Example 3, a molding compoundprepared from 47 parts resin syrup, 17.9 parts alpha flock, and 0.22part chloroacetamide, was molded at 135 C. and 6000 pounds pressure for5 minutes. It had a good, hard cure and the molded piece waslight-colored and translucent.

Example 7 M 01 ratio Parts by (approx) weight The above were refluxedfor 30 minutes. A precipitate appeared in the hot reaction mass. At 130C., the product had a very good cure. The addition of chloroacetamideaccelerated the cure and produced a powdery cured mass. A moldingcompound consisting of a mixture of 59 parts of resin and 22.5 partsalpha flock, which mixture had been air-dried for 48 hours andthereafter oven-dried at 70 C. till dry, was molded at 135 C. and 6000pounds per square inch pressure for minutes. The compound had a fairlysoft cure. The molded piece had a rather dull surface and was opaque.Repeating the prepartion of the molding compound but incorporating 0.5part chloroacetamide or alpha, betadichloropropionitrile produced amolded piece that was hard and glossy and had good water resistance.

Example 8 Mol ratio (approx) Parts by weight Aqueous di-carbamidomethylurea (28% urea Aqueous formaldehyde were refluxed for 29 minutes to forma syrup which was clear while hot and cloudy at room temperature andwhich had a pH=4.65. It had a good cure at 130 C. With chloroacetamide,the cure was very fast. A molding compound consisting of a mixture 01 59parts syrup and 22.5 parts alpha flock, which had been dried at roomtemperature for 48 hours and oven-dried at 50 C. till dry, was molded at135 C. and 6000 pounds per square inch pressure for 5 minutes. Thecompound had a good cure and the molded article was hard and had aslightly yellow cast.

Example 9 Mol ratio Parts by (approx) weight Aqueous di-carbamldomethylurea 28% echo. 1 357.0 Para toluene sulionamide 1 83. 8 Aqueousformaldehyde 6 235 The resin syrup obtained by refluxing the above for30 minutes was clear while hot and precipitated on cooling. It had along rubbery cure at C. The cure was accelerated and fairly hard withsmall additions of chloroacetamide.

Example 10 Mol ratio Parts by (approx.) weight Aqueousdi-carbamidomethyl urea (28% cone.) 1 357. 0 Phenol 1 40. 0 Aqueousformaldehyde. 6 235. 0 NaOH (in 10 parts water). 0.01 0.2

Example 11 Mol ratio Parts by (approx) weight Aqueous di-carbamidomethylurea (28% conc. 1 357.0 Melamine 1 01.8 Aqueous formaldehyde 7 274. 0

The above were refluxed for 19 minutes. The resultant syrup, which wasclear while hot but cloudy on cooling, did not cure alone at 130 C. Withsmall additions of chloroacetamide, the cure was excellent.

Example 12 M01 ratio Parts by (apprmn) weight Aqueous dl-carbamidomethylurea (28% oonc.) 1 357.0 Dimethylol urea (containing 11% H;0) 12 792.0 NH: (in aqueous solution) M l. 0 Distilled water 1,000

The syrup obtained after refluxing the above mixture for 30 minutes wasclear while hot and precipitated on cooling. It had a pH of 6.6. Thesyrup did not cure alone at 130 C. With chloroacetamide a very good curewith a prolonged tacky stage was obtained.

The urea derivative was mixed with the formaldehyde and the mixture wasbrought to reflux. The melamine methylol was then added and refluxcontinued for 30 minutes. The syrup product was clear while hot andcloudy on cooling. It had a pH of 6.5 5. The cure alone at 130 C. wasvery slow and rubbery. With chloroacetamide, it was excellent and hard.

Example 14 M01 ratio Parts by (approx) weight Aqueous di'carbamidomethylol urea (28% I 357 A ueou'rlifiiiif 'di 4 157 Gl yce e 10%15 NaOH (in 10 parts water) 0.01 o. 2

The above were refluxed for 30 minutes to form a syrup that was clearwhile hot and cloudy on cooling. It had a pH of 6.85. At 130 C. it didnot cure alone. With the addition of chloroacetamide, the cure was slowand rubbery.

Example 15 M01 ratio Parts by (approxJ weight Aqueous di-carbamidomethylurea (28% cone. l 357 Aqueous formaldehyde 4 157 Butyl alcohol 20% 32NaOH (in 10 parts water) 0.01 0. 2

were refluxed for 30 minutes. The resinous syrup so obtained was clearwhile hot and cloudy on cooling. It had a pH of 7.0 When heated on thehot plate, it bodied to a clear, hard resin.

were refluxed for 30 minutes. The resultant syrup was clear while hotand cloudy on cooling and had a pH of 6.8. At130 0., it.had no up parenttendency to cure alone. With chloroacetamide, the cure was very slow,but good.

Example 17 M01 ratio Parts by (approxJ weight Aqueous di-carbamidomethylurea (28% mm 1 357.0 Agneous iormaldehyde 4 167. N a (in aqueoussolution) M i. 0 Acatamlde 20% 3.2

The above were refluxed for 30 minutes. The resulting syrup having apHof 4.9 was clear while sired in the finished product.

hot and cloudy on cooling. At 130 C. the cure alone was very slow andsoft. The addition of chloroacetamide gave a product that cured quicklyto a hard state.

Although in the above examples I have shown A that satisfactory moldingcompounds can. be made without the use of curing agents, or curingreactants, the use of such curing accelerators is recommended wheremolded pieces having.

maximum gloss and water resistance mum molding time are desired.

In producing any of these new condensation products, the choice oi thealdehyde component is dependent largely upon economic considerations andthe particular properties de- I prefer to use as the aldehyde reactant,formaldehyde or compounds engendering formaldehyde. e. g.,paraformaldehyde, hexamethylene tetramine. etc. For some applications Imay use, for instance, acetaldehyde, propionaldehyde, butyraldehyde,acrolein, methacrolein, crotonaldehyde. benzaldehyde, furfural, etc..mixtures thereof, or mixtures of formaldehyde (or compounds engenderingformaldehyde) with such aldehydes. Various aldehyde-addition productsmay be used instead of aldehydes. Such products include the monoand poly(N-carbinol) derivatives, more particularly the monoand polymethylolderivatives. of urea, thiourea, selenourea, and iminourea, substitutedureas, thioureas, selenoureas, and iminoureas, amides or polycarboxylicacids, e. g.; maleic, itaconic, iumaric. adipic, malonic, citric,phthalic, etc. I may also use with particularly good results, themethyiol amino triazines. e. g., mono-. di-. tri-, tetra-, penta-, andhexa-methylol melamines; the methylol amino diazines, e. g., trimethylol1,3,5-triamino pyrimidine; the amino triazoles, e. g., dimethylolguanazole, etc. mixtures of these materials or mixtures of an aldehydewith such materials may also be used.

The ratio of aldehydic reactant to the urea derivatives of thisinvention may be varied over a wide range but ordinarily is of the ordercorresponding to at least, one mol of the aldehyde, or an equivalentamount of an aldehyde engenderingor addition products, for each mol ofand minithe urea derivative. Thus, I may use, for example, from one tofive or six mols, preferably 3 mols, of an aldehyde for each mol of thederivatives.

In producing these various condensation products, dyes, pigments,plasticizer, mold lubricants, opaciflers, and various fillers (e. g.wood flour, glass flbers,asbestos, mineral wool, mica, cloth cuttings,etc.) may be compounded with the resin in accordance with conventionalpractice to provide various thermoplastic and thermosetting moldingcompositions.

The modified or unmodified resinous compositions of this invention havea wide variety of uses. For example, in addition to their use in theproduction of molding compositions, they may be used as modifiers ofother natural and synthetic resins, as laminating varnishes in theproduction of laminated articles wherein sheet materials, e. g., paper,cloth, sheet asbestos, etc. are coated and impregnated with the resin.superimposed and thereafter united under heat and pressure. They may beused in the production oi wire or baking enamels, for bonding orcementing together mica flames to form a laminated mica article, forbonding together abrasive grains in the production of resin-bondedstones, sandpapers; etc. They also may be employed for treating cotton,linen, and other celiulosic materials in sheet or other form or asimpregnants for electrical coils and for other electrically insulatingapplications.

What I claim as new and desire to secure by Letters Patent oi the UnitedStates, is:-

1. A composition comprising the product of reaction of melamine,formaldehyde, and an organic compound or the formula.

- RHNcYNmcHR'NRcYNRnH where Y is a member of the classconsisting ofoxygen and sulphur, R. is a member of the class consisting of hydrogen"and monovalent hydrocarbon radicals of not more than six carbon atoms,R is a member of the class consisting of hydrogen, monovalenthydrocarbon-radicals, and monovalent halogeno-substituted hydrocarbonradicals and n is an integer and is at least 1 and not more than 2.

2. A heat-curable composition comprising the heat-convertible product ofreaction of (1) a partial condensation product of ingredients comprisingmelamine, an aldehyde and an organic compound of the general formulaRnNcYNmcHwNacYNm-H abrasive articles such. for instance. as grindwhere Yis a member of the class consisting oi oxygen and sulphur, R. is amember of the class consisting of hydrogen and a monovalent hydrocarbonradical of not more than six carbon atoms,

- R is a member of the class consisting of hydrogen and monovalenthydrocarbon and halogeno-hydrocarbon radicals and n is an integer and isat least 1 and not more than 2, and (2) an alpha,beta-dichloropropionitrile.

3. A product comprising the heat-cured composition of claim 2.

4. The method of preparing new condensation products which compriseseffecting reaction between ingredients comprising melamine, an aidehydeand an organic compound corresponding to the formula RHNCYNR(CHR'NRCYNR)"H where Y is a member of the class consisting of .oxygen and sulphur, Ris a member of the class GAETANO F. DALELIO.

CERTIFICATE OF CORRECTION. v Patent No. 2,559,621. January 18, 19M.

GAEITANO F. D'ALEL'IO.

of the above numbered potent requiring correction as follows: Page 2,first column, line 69, for "co;!.1--mod.iffl.etil' read--oil-modif1edpage 5, second -column, l1ne 51 for the word 'has" read--had--- line 147, in the table,

last column thereof, for "115.0' read --l57.0--; line 51, for "was" readpage 1;, first column, like 50, strike out "of" before --res1n---;

endthat the said Letters Patent should be'read with this correctiontherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 18th aw o'r'A m-i, A..D.-. 191m.

Leslie Frazer (Seal) Acting Commissioner of Patents;

